I've been looking for a place to express an opinion.A little LONG range back round. Climate change in Earth's geological history is CYCLICAL. There are many factors which can be addressed. Ice age happenings, precession of the Earth's axis, even fluctuations in sunspots and solar output should be considered. Also volcanic eruptions and natural forest and brush fires must be included. BUT there is NO doubt that the human contribution of fossil fuel burning has accelerated this phenomenon.Always loved science. Earth Day was established when I was a freshman in high school (4/22/70). That was 45 years ago. Even then concerns were being raised about climate and environmental changes.Fast forward to the 1980's. Scientists really started to raise red flags and predicting these weather events. That was over 30 years ago.NOW 2016. Look at the Polar icecaps. Look at how mountain glaciers around the world are melting. Look at the severity of hurricanes, tornadoes, floods and other extreme weather events that are taking place. This was all predicted way back then.The Paris signing of COP21 is HOPING to reduce carbon emissions by 2100a.d. THAT'S ALMOST 80 YEARS!!!All things considered...geological and astronomical effects, combined with natural and human contributions, I really believe we, and the Earth, are at a point of no return.THANK YOU FOR YOUR TIME READING AND LISTENING...GAIL

At 4/26/2016 4:31:12 AM, GirlsRNerds2 wrote:I've been looking for a place to express an opinion.A little LONG range back round. Climate change in Earth's geological history is CYCLICAL. There are many factors which can be addressed. Ice age happenings, precession of the Earth's axis, even fluctuations in sunspots and solar output should be considered. Also volcanic eruptions and natural forest and brush fires must be included. BUT there is NO doubt that the human contribution of fossil fuel burning has accelerated this phenomenon.Always loved science. Earth Day was established when I was a freshman in high school (4/22/70). That was 45 years ago. Even then concerns were being raised about climate and environmental changes.Fast forward to the 1980's. Scientists really started to raise red flags and predicting these weather events. That was over 30 years ago.NOW 2016. Look at the Polar icecaps. Look at how mountain glaciers around the world are melting. Look at the severity of hurricanes, tornadoes, floods and other extreme weather events that are taking place. This was all predicted way back then.The Paris signing of COP21 is HOPING to reduce carbon emissions by 2100a.d. THAT'S ALMOST 80 YEARS!!!All things considered...geological and astronomical effects, combined with natural and human contributions, I really believe we, and the Earth, are at a point of no return.THANK YOU FOR YOUR TIME READING AND LISTENING...GAIL

At 4/26/2016 4:31:12 AM, GirlsRNerds2 wrote:All things considered...geological and astronomical effects, combined with natural and human contributions, I really believe we, and the Earth, are at a point of no return.

Welcome, Gail -- great handle, and thanks for your thoughts.

Unfortunately, nature doesn't really cycle; it spirals into heat-death. Life on Earth can only exist at all because it accelerates the entropy of the planet. It mainly does this by taking incident sunlight, and trapping it as heat-energy on the surface, instead of letting it radiate it back out.

Plants do this with photosynthesis, for example: sunlight becomes sugars, which eventually decompose to become heat. Animals accelerate this when they consume plants and expel CO2 and methane. Essentially, all life accelerates planetary heat-death, and human engineering happens to be more efficient at it than the efforts of any other species, since we can burn trees and grasses, raise cows, breed dogs (which can have a higher carbon footprint than some SUVs), and exhume the bodies of hundred-million year-old algae as oil, coal and gas, and burn that too.

So the question isn't really how to sustain our habitat indefinitely, but how to delay its inevitable destruction. The big, hard limits on planetary life are the sun's death (our middle-aged sun is estimated 4.5 billion years old, and expected to die in 5 billion years time), and an imminent collision between our galaxy and that of Andromeda (about 4 billion years away.) So all going well, our galaxy will die before our sun will... but you're right: we could mismanage resources and habitat so badly that humans will become extinct long before that.

It won't kill all life on our planet -- just us, and a number of vulnerable and apex species. But our planet also does this -- some 99% of all species that ever existed are already extinct. If we can be smarter, we can make this a planet highly suited for our own long-term habitation; or we can be dumb and go the way of other species that don't adapt terribly well.

At 5/7/2016 7:57:28 PM, RuvDraba wrote:So the question isn't really how to sustain our habitat indefinitely, but how to delay its inevitable destruction.

Simple. Just raise taxes and that magically solves everything.

Science in a nutshell:
"Facts are neither true nor false. They simply are."
"All scientific knowledge is provisional. Even facts are provisional."
"We can be absolutely certain that we have a moon, we can be absolutely certain that water is made out of H2O, and we can be absolutely certain that the Earth is a sphere!"
"Scientific knowledge is a body of statements of varying degrees of certainty -- some most unsure, some nearly sure, none absolutely certain."